1. Technical Field
The present invention relates to an electron gun, and more particularly, to a cathode assembly forming an electron emission source and an inline electron gun for a color picture tube using the cathode assembly.
2. Related Art
Typically, an electron gun for a color picture tube is installed at a neck portion of a cathode ray tube and emits an electron beam to excite a fluorescent film. An electron gun for a color picture tube includes a cathode assembly, a control electrode installed adjacent to the cathode assembly, a screen electrode. The electron gun also includes a plurality of focus electrodes installed sequentially in a direction away from the screen electrode.
In the electron gun for a color picture tube having the above structure, as a predetermined electric potential is applied to each of the electrodes, an electron beam is emitted from electron emission substance of the cathode assembly. The emitted electron beam is focused and accelerated by an electron lens formed between the respective electrodes and selectively deflected according to the position of scanning of a fluorescent film, thus landing onto a fluorescent film.
In the above electron gun, the cathode assembly as an electron emission source should have a thermal and structural stability and exhibit a superior assembly feature and a superior welding feature with respect to a metal tape to be described later.
A cathode support frame can include glass and pipes installed inline at the glass. The pipes are exposed to facilitate welding between the pipes and a metal tape. However, when metal tape is welded to the pipes, cracks are generated in the glass due to a pressing force of a welding rod and due to an inferior assembly.
It would be beneficial to minimize the cracks or eliminate the cracks, and it would be beneficial to develop an improved assembly with improved welding characteristics. Efforts have been made to improve cathode supporting structures. An exemplar of a recent effort in the art is as follows: U.S. Pat. No. 5,099,170 for CATHODE SUPPORTING STRUCTURE FOR COLOR CATHODE RAY TUBE issued on 24 Mar. 1992.
While that recent effort pertains to cathode supporting structures, it is not believed to adequately provide an improved, efficient, and convenient cathode assembly and color picture tube utilizing the same.